Knoxville Tn metro area. This is the Isshinryu capitol of the USA. Long, Wheeler, and Hatcher. Karate/TKD/TSD about 80%. Shaolin KF, Kung Fu, tai chi (2 types one fru-fru bunny hugger non-sense and one kick your teeth in MA), generic escrima/kali, bagua, h-ising, Clear's Silat, Serak Silat, Pekiti Tersia Kali, Inayan Eskrima (one of Mike Inay's senior students is here), Krava Maga, Vale Tudo, Shoot wrestling, boxing, Jun Fan, WC, and probably a few I don't have some "inside" connection family arts. Most of the above are private ya gotta know somebody private classes. Most of the open schools are McDojo's of the first order. I say that having spent most of the last 20yrs looking for someone with their head out of their backside. Pure chance (read another web forum) put me onto my current school and there I met people doing some of the above cross training in Serak Silat and finishing the Pekiti system.

As for the percentage, currently active, who knows for sure, but I'd guess 70% of the people have study some karate/judo/wrestling during their lifetime.

Pretty much every style of martial arts exists here, cannot even name most of them. Some legit ones, some mcdojos.

Main MAs being: Karate, Wing Chun, Tae Kwon Do, jeet kune do, All that fitness stuff like cardio kickboxing and "body combat", judo, boxing not nearly as much as in america.
Stuff like BJJ and muay thai exists but i dont know much about the schools in sydney, but they arent very common.

About 3 capoeira schools teaching across many suburbs, ninjutsu place, some weird "steel body" place where they teach you to strengthen your body so it can get run over with a 4WD. i downloaded video it got like 5 people lying down and having a 4WD run ova them.

Denver, Colorado.
We have everything except (as far as I know, and if someone would correct me I would appreciate it)an accredited JKD school, although Dan Inosanto apparently supported a Pencak Silat school here.
(?)...

If Clarence Thatch is still teaching in Denver I believe he is an accredited JKD instructor. His school (when I lived in Denver) was called "3D Martial Arts" he used to have a alot of guest seminars from the Gracie crew and Inosanto.

Gibraltar is a britsh colony on the southern tip of Spain, across the sea from morocco. Here there is a jujitsu club (which I belong to), a shototkan karate club(which I am thinking of joining), a TKD club, and a boxing club. Not really my ideal range of choices, but good enough, I think.

Tampa Florida
lotsa TKD and karate, Tang soo doo, hapkido, wah lum kung fu, tai chi, aikido, silat and judo. oh my god i looked in the phone book and theres actually a american ninja secret society and im suspicious of this other place i cant decide if its a karate place or a strip club but its called afterkicks. I'ts in the MA section of the phonebook but.... oh and how can i forget the purple dragon don- jiysu-ryu with the technique of the month.(while someone is trying to stab you take off your belt and indiana jones it around their neck to rip the flesh off.)

*What part of the country do you live in?
Las Vegas NV
*What's the distribution of MA schools in your area, with a rough percentage of the arts represented?
Hard to say really her ein vegas there's a martial arts club all over the place.
*Are there any unique/uncommon martial arts offered in your area besides the normal TKD/Karate/etc, including MMA/NHB fight teams?
J-sect is out here. Thats really the only "special" team or club I can think of.
*If you had to guess (unless you know for some reason) what percentage of people in the general community in your area are active participants in the martial arts?
Like I said it's Veags so **** hard to say how many people move/ get trapped here every week. LOL

If you knew you'd die in a fight tommorow. Would you still train to win?"